A retired University of Illinois physicist is questioning whether a Nobel Prize awarded Tuesday to two Japanese and a Japanese-born American scientist ignores the work he and others did to invent the world's first LED.

Nick Holonyak (HOHL'-nyak) Jr. invented that first, red light-emitting diode back in 1962. Some colleagues have said the invention deserved the Nobel. Holonyak never won the honor and never asserted he deserved it.

But on Tuesday the 85-year-old Holonyak called the decision to bypass his work "insulting." He said the award winners' blue LED wouldn't be possible without his invention.

LEDs have made fiber-optics networks, DVDs and a range of other technologies possible.

University of Louisville professor Delaina (de-LAY'-nuh) Amos works with LEDs. She said the blue LED deserves the award, but so does Holonyak's.